<input input-focus ng-show="interval === 'other'"
  class="form-control timelion-interval"
  ng-model="otherInterval">

<select class="form-control timelion-interval timelion-interval--select"
  ng-options="i for i in intervalOptions"
  ng-class="{'timelion-interval-other': interval == 'other'}"
  ng-model="interval"></select>
